Paddington train derailed due to decayed timbers

The train derailed as it was leaving Paddington station

A Paddington train derailed due to decayed timbers under the tracks, the Rail Accident Investigation Branch (RAIB) has ruled.

The train derailed at low speed on its way out of the station on 20 August.

The RAIB said the longitudinal timbers that run parallel to the rail had decayed, allowing the rail to move outwards.

This allowed the wheels of the train's rear power car to fall into the space in between.

The timber failed as the train passed over it

The RAIB said that the failed timbers had been identified as needing replacement during the previous annual inspection.

The inspection report said they were being damaged by water and toilet waste leaking from trains.

But the work was postponed until September so that a project linked to the electrification of the Great Western Main Line could be carried out.

The RAIB said appropriate priority needed to be given to repairing the timbers.

It added that the risk of infrastructure failure must be taken into account when delaying such remedial work for other projects.